The present invention relates to a clinical test apparatus for performing clinical analysis based on color reaction of a test piece impregnated with an analyte. More particularly, the present invention relates to a clinical test apparatus in which the test piece undergoes reaction on a rotary reaction table at a predetermined temperature.
This kind of clinical test apparatus is known which, in one example, comprises a reaction table for placing a urine test piece which is impregnated with urine as an analyte for reaction therewith to determine the concentration of a urine constituent on color reaction of the test piece.
This kind of clinical test apparatus mainly includes a reaction table rotated by the driving force of a stepping motor via a drive shaft, a measuring/testing section for directing light to a predetermined position on the reaction table and for determining the concentration of an urine constituent on the basis of the light reflected on the urine test piece which has undergone color reaction, and a suction device for sucking an excess of urine deposited on the urine test piece and/or the reaction table.
However, the suction device is incapable of completely removing the urine excess deposited on the urine test piece and the reaction table. As a result, the reaction table is easily contaminated with urine and therefore is likely to a become unclean. Accordingly, the reaction table should be removed from the apparatus body for the purpose of cleaning with water for example before or after the analysis of the urine test piece.
Further, for improving the accuracy of analysis in such a clinical test apparatus, it has been proposed to cause the urine test piece to react with urine at a predetermined temperature. For instance, a heater may be disposed near the reaction table to raise the temperature of the atmosphere around the reaction table, or a heat plate is provided in direct contact with the reaction table to raise the temperature from outside the reaction table.
However, in such a conventionally proposed apparatus, heat is transmitted to the reaction table from outside; i.e., from a heater disposed near the reaction table or from a heat plate disposed indirect contact with the reaction table, for example. As a result, heat cannot be efficiently transmitted to the urine test piece placed on the reaction table, and therefore, it has been difficult to analyze the urine test piece at an appropriate temperature.
It is, therefore, an object of the present invention to provide a clinical test apparatus wherein heat is transmitted from inside the reaction table to the urine test piece for analyzing the urine test piece on the reaction table at an appropriate temperature while making the reaction table removable from the apparatus body for cleaning purposes.
In accordance with the present invention, there is provided a clinical test apparatus for measuring/testing a test piece which is impregnated with an analyte and placed on a reaction table for reaction with the analyte at a predetermined temperature, the apparatus comprising: a primary coil provided at a position adjacent the reaction table and supplied with alternating power; a secondary coil provided on the reaction table in facing relation to the primary coil for inducing an electromotive force due to the alternating power supplied to the primary coil; and a heater mounted to the reaction table for generating heat due to the electromotive force induced in the secondary coil.
With the clinical test apparatus having the above structure, when AC power is supplied to the primary coil provided adjacent the reaction table, an electromotive force is induced in the secondary coil provided on the reaction table in facing relation to the primary coil due to electromagnetic induction. The heater mounted on the reaction table generates heat by utilizing the electromotive force thus induced in the secondary coil 2. Thus, the heat is directly transmitted from the heater to the test piece on the reaction table, thereby enabling reliable heat transfer to the test piece.
Accordingly, with the clinical test apparatus described above, it is possible to analyze the test piece at an appropriate temperature owing to reliable heat transfer to the test piece placed on the reaction table. Further, since the reaction table can be supplied with electrical power without any electrical contact, it is possible to remove the reaction table from the apparatus body.
In a preferred embodiment, the reaction table incorporates a temperature control means for controlling the temperature of the reaction table by controlling the power supply from the secondary coil to the heater. For instance, the temperature control means is operative to reduce the power supply from the secondary coil to the heater when the temperature of the reaction table rises above a predetermined temperature, whereas it increases the power supply when the temperature of the reaction table drops below the predetermined temperature. As a result, the heating operation of the heater is controlled in a feedback manner on the basis of the temperature of the reaction table, thereby keeping the temperature of the reaction table at a predetermined level.
Therefore, in this preferred embodiment, it is possible to maintain the temperature of the reaction table at a constant level which is appropriate for reaction of the test piece with the analyte.
In a preferred embodiment, the reaction table is centrally supported at the center by a drive shaft, and the primary coil and the secondary coil are wound around the drive shaft and spaced from each other.
With such an arrangement, when the drive shaft rotates, the reaction table supported at the center by the drive shaft also rotates. As a result, the secondary coil provided on the reaction table also rotates around the drive shaft while keeping a predetermined spacing from the primary coil. Thus, when alternating magnetic flux is generated along the drive shaft due to alternating current supplied to the primary coil, the magnetic flux also penetrates centrally through the secondary coil wound around the drive shaft. As a result, an electromotive force is properly induced in the secondary coil due to electromagnetic induction.
In a preferred embodiment, the primary coil is sealed at a position adjacent the reaction table, whereas the secondary coil is sealed on the reaction table.
With such a structure, the primary coil and the secondary coil are prevented from water penetration. Accordingly, it is possible to wash the reaction table or the nearby components with water for example without causing a trouble.
In a preferred embodiment, the reaction table is removable.
With such a structure, it is possible to keep the reaction table in its mounted position during analysis of the test piece, and to remove the same when it is out of service. Thus, the entire reaction table and the nearby components can be manually reached for cleaning, thereby facilitating washing of the reaction table and the nearby components with by water for example.
Other features and advantages of the present invention will become apparent from the detailed description given below with reference to the accompanying drawings.